Adherent Biofilms in Bacterial Vaginosis

Unraveling the interplay between unicellular parasites and bacterial biofilms: Implications for disease persistence and antibiotic resistance

Bacterial biofilms have attracted significant attention due to their involvement in persistent infections, food and water contamination, and infrastructure corrosion. This review delves into the intricate interactions between bacterial biofilms and unicellular parasites, shedding light on their impact on biofilm formation, structure, and function. Unicellular parasites, including protozoa, influence bacterial biofilms through grazing activities, leading to adaptive changes in bacterial communities. Moreover, parasites like Leishmania and Giardia can shape biofilm composition in a grazing independent manner, potentially influencing disease outcomes. Biofilms, acting as reservoirs, enable the survival of protozoan parasites against environmental stressors and antimicrobial agents. Furthermore, these biofilms may influence parasite virulence and stress responses, posing challenges in disease treatment. Interactions between unicellular parasites and fungal-containing biofilms is also discussed, hinting at complex microbial relationships in various ecosystems. Understanding these interactions offers insights into disease mechanisms and antibiotic resistance dissemination, paving the way for innovative therapeutic strategies and ecosystem-level implications.

Polymicrobial consortia in the pathogenesis of biofilm vaginosis visualized by FISH. Historic review outlining the basic principles of the polymicrobial infection theory

The manuscript disputes the exclusive mono-infectious way of thinking, which presumes that for every infection only one pathogen is responsible and sufficient, when infectious vectors, close contact and reduced immunity meet. In situations involving heavily colonized anatomical sites such an approach often ends in insoluble contradictions. Upon critical reflection and evaluation of 20 years research on spatial organization of vaginal microbiota it is apparent, that in some situations, pathogens may act and operate in permanent, structurally organized consortia, whereas its individual components may be innocuous and innocent, failing to express any pathogenic effect. In these cases, consortia are the true pathogens responsible for many infectious conditions, which usually remain unrecognized as long as improperly diagnosed. The structure of such consortia can be unraveled using ribosomal fluorescence in situ hybridization (FISH). FISH methodology, that not only offers an ex vivo opportunity to recognize bacterial species, but provides unique physical insight into their specific role in the pathogenesis of polymicrobial infections. Ribosomal FISH technique applied to both, women with bacterial vaginosis (BV) and their male partners, has added significantly to our understanding of the pathogenesis of this condition and contributed to appreciating the mechanisms of polymicrobial, community-based infection, potentially leading to therapeutic advances.

Gardnerella Species and Their Association With Bacterial Vaginosis

BACKGROUND

Bacterial vaginosis (BV) is a condition marked by high vaginal bacterial diversity. Gardnerella vaginalis has been implicated in BV but is also detected in healthy women. The Gardnerella genus has been expanded to encompass 6 validly named species and several genomospecies. We hypothesized that particular Gardnerella species may be more associated with BV.

METHODS

Quantitative polymerase chain reaction (PCR) assays were developed targeting the cpn60 gene of species groups including G. vaginalis, G. piotii/pickettii, G. swidsinskii/greenwoodii, and G. leopoldii. These assays were applied to vaginal swabs from individuals with (n = 101) and without BV (n = 150) attending a sexual health clinic in Seattle, Washington. Weekly swabs were collected from 42 participants for up to 12 weeks.

RESULTS

Concentrations and prevalence of each Gardnerella species group were significantly higher in participants with BV; 91.1% of BV-positive participants had 3 or more Gardnerella species groups detected compared to 32.0% of BV-negative participants (P < .0001). BV-negative participants with 3 or more species groups detected were more likely to develop BV within 100 days versus those with fewer (60.5% vs 3.7%, P < .0001).

CONCLUSIONS

These results suggest that BV reflects a state of high Gardnerella species diversity. No Gardnerella species group was a specific marker for BV.

Beyond antibiotics: CRISPR/Cas9 triumph over biofilm-associated antibiotic resistance infections

A complex structure known as a biofilm is formed when a variety of bacterial colonies or a single type of cell in a group sticks to a surface. The extracellular polymeric compounds that encase these cells, often consisting of proteins, eDNA, and polysaccharides, exhibit strong antibiotic resistance. Concerns about biofilm in the pharmaceutical industry, public health, and medical fields have sparked a lot of interest, as antibiotic resistance is a unique capacity exhibited by these biofilm-producing bacteria, which increases morbidity and death. Biofilm formation is a complicated process that is controlled by several variables. Insights into the processes to target for the therapy have been gained from multiple attempts to dissect the biofilm formation process. Targeting pathogens within a biofilm is profitable because the bacterial pathogens become considerably more resistant to drugs in the biofilm state. Although biofilm-mediated infections can be lessened using the currently available medications, there has been a lot of focus on the development of new approaches, such as bioinformatics tools, for both treating and preventing the production of biofilms. Technologies such as transcriptomics, metabolomics, nanotherapeutics and proteomics are also used to develop novel anti-biofilm agents. These techniques help to identify small compounds that can be used to inhibit important biofilm regulators. The field of appropriate control strategies to avoid biofilm formation is expanding quickly because of this spurred study. As a result, the current article addresses our current knowledge of how biofilms form, the mechanisms by which bacteria in biofilms resist antibiotics, and cutting-edge treatment approaches for infections caused by biofilms. Furthermore, we have showcased current ongoing research utilizing the CRISPR/Cas9 gene editing system to combat bacterial biofilm infections, particularly those brought on by lethal drug-resistant pathogens, concluded the article with a novel hypothesis and aspirations, and acknowledged certain limitations.

Characterization of a Lactobacillus gasseri strain as a probiotic for female vaginitis

Vaginitis, a prevalent gynecological condition in women, is mainly caused by an imbalance in the vaginal micro-ecology. The two most common types of vaginitis are vaginal bacteriosis and vulvovaginal candidiasis, triggered by the virulent Gardnerella vaginalis and Candida albicans, respectively. In this study, a strain capable of inhibiting G. vaginalis and C. albicans was screened from vaginal secretions and identified as Lactobacillus gasseri based on 16S rRNA sequences. The strain, named L. gasseri VHProbi E09, could inhibit the growth of G. vaginalis and C. albicans under co-culture conditions by 99.07% ± 0.26% and 99.95% ± 0.01%, respectively. In addition, it could significantly inhibit the adhesion of these pathogens to vaginal epithelial cells. The strain further showed the ability to inhibit the enteropathogenic bacteria Escherichia coli and Salmonella enteritidis, to tolerate artificial gastric and intestinal fluids and to adhere to intestinal Caco-2 cells. These results suggest that L. gasseri VHProbi E09 holds promise for clinical trials and animal studies whether administered orally or directly into the vagina. Whole-genome analysis also revealed a genome consisting of 1752 genes for L. gasseri VHProbi E09, with subsequent analyses identifying seven genes related to adhesion and three genes related to bacteriocins. These adhesion- and bacteriocin-related genes provide a theoretical basis for understanding the mechanism of bacterial inhibition of the strain. The research conducted in this study suggests that L. gasseri VHProbi E09 may be considered as a potential probiotic, and further research can delve deeper into its efficacy as an agent which can restore a healthy vaginal ecosystem.

Dysbiosis in pregnant mice induced by transfer of human vaginal microbiota followed by reversal of pathological changes in the uterus and placenta via progesterone treatment

OBJECTIVE

The vaginal microbiota dysbiosis induces inflammation in the uterus that triggers tissue damage and is associated with preterm birth. Progesterone is used to prevent labor in pregnant women at risk of preterm birth. However, the mechanism of action of progesterone still needs to be clarified. We aimed to show the immunomodulatory effect of progesterone on the inflammation of uterine tissue triggered by dysbiotic vaginal microbiota in a pregnant mouse model.

METHODS

Healthy (n = 6) and dysbiotic (n = 7) vaginal microbiota samples isolated from pregnant women were transferred to control (n = 10) and dysbiotic (n = 14) pregnant mouse groups. The dysbiotic microbiota transferred group was treated with 1 mg progesterone (n = 7). Flow cytometry and immunohistochemistry analyses were used to evaluate inflammatory processes. Vaginal microbiota samples were analyzed by 16 S rRNA sequencing.

RESULTS

Vaginal exposure to dysbiotic microbiota resulted in macrophage accumulation in the uterus and cellular damage in the placenta. Even though TNF and IL-6 elevations were not significant after dysbiotic microbiota transplantation, progesterone treatment decreased TNF and IL-6 expressions from 49.085 to 31.274% (p = 0.0313) and 29.279-21.216% (p = 0.0167), respectively. Besides, the macrophage density in the uterus was reduced, and less cellular damage in the placenta was observed.

CONCLUSION

Analyzing the vaginal microbiota before or during pregnancy may support the decision for initiation of progesterone therapy. Our results also guide the development of new strategies for preventing preterm birth.

Compositional and functional differences of the vaginal microbiota of women with and without cervical dysplasia

Alterations in the vaginal microbiota, including both species composition and functional pathways, have been associated with HPV infection and progression of dysplasia to cervical cancer. To further explore this, shotgun metagenomic sequencing was used to taxonomically and functionally characterize the vaginal microbiota of women with and without cervical dysplasia. Women with histologically verified dysplasia (n = 177; low grade dysplasia (LSIL) n = 81, high-grade dysplasia (HSIL) n = 94, cancer n = 2) were compared with healthy controls recruited from the cervical screening programme (n = 177). Women with dysplasia had a higher vaginal microbial diversity, and higher abundances of Gardnerella vaginalis, Aerococcus christensenii, Peptoniphilus lacrimalis and Fannyhessea vaginae, while healthy controls had higher relative abundance of Lactobacillus crispatus. Genes involved in e.g. nucleotide biosynthesis and peptidoglycan biosynthesis were more abundant in women with dysplasia. Healthy controls showed higher abundance of genes important for e.g. amino acid biosynthesis, (especially L-lysine) and sugar degradation. These findings suggest that the microbiota may have a role in creating a pro-oncogenic environment in women with dysplasia. Its role and potential interactions with other components in the microenvironment deserve further exploration.

The role of probiotics as adjunct treatment in the prevention and management of gynecological infections: An updated meta-analysis of 35 RCT studies

OBJECTIVE

The present study aims to conduct a comprehensive meta-analysis of randomized controlled trials (RCTs) investigating the efficacy of probiotics as an adjunct treatment for preventing and treating gynecological infections.

MATERIALS AND METHODS

The study adopted a systematic review of scientific databases including PubMed, Cochrane, and EMBASE, using defined MeSH terms. The inclusion and exclusion criteria were set to refine the search, with the data extraction and quality assessment being conducted by two independent investigators.

RESULTS

A total of 35 articles, comprising 3751 patients, were included in the meta-analysis. The application of probiotics demonstrated a notable increase in the cure rates of bacterial vaginosis (BV) and vulvovaginal candidiasis (VVC) as compared to control groups. A significant BV cure rate (OR: 5.972; 95% CI: 2.62-13.59; p-value: 0.01) was noted with probiotic use, which was even more pronounced when used as an adjunctive treatment with antibiotics (OR: 2.504; 95% CI: 1.03-6.06; p-value: 0.04). Additionally, probiotic use significantly reduced the recurrence rates of BV (OR: 0.34; 95% CI: 0.167-0.71; p-value: 0.004). For VVC, a significant increase in the cure rate was observed in the probiotic group (OR: 3.425; 95% CI: 2.404-4.879; p-value: 0.01), along with a lower recurrence rate (OR: 0.325; 95% CI: 0.175-0.606; p-value: 0.01).

CONCLUSION

Our findings underscore the potential role of probiotics as a beneficial adjunctive treatment for gynecological infections, indicating an improved cure rate and decreased recurrence. However, additional well-designed studies are necessary to corroborate these findings.

Medical-Grade Honey as a Potential New Therapy for Bacterial Vaginosis

The prevalence of bacterial vaginosis (BV) among women of reproductive age is 29%. BV arises from a vaginal imbalance marked by reduced levels of lactic acid-producing lactobacilli and an overgrowth of pathogenic anaerobes. The multifactorial nature of BV's pathogenesis complicates its treatment. Current antibiotic therapy exhibits a recurrence rate of about 60% within a year. Recurrence can be caused by antibiotic treatment failure (e.g., due to antimicrobial resistance), the persistence of residual infections (e.g., due to biofilm formation), and re-infection. Because of the high recurrence rates, alternative therapies are required. Medical-grade honey (MGH), known for its antimicrobial and wound healing properties in wound care, emerges as a potential novel therapy for BV. MGH exerts broad-spectrum antimicrobial activity, employing multiple mechanisms to eliminate the risk of resistance. For example, the low pH of MGH and the production of hydrogen peroxide benefit the microbiota and helps restore the natural vaginal balance. This is supported by in vitro studies demonstrating that MGH has an antibacterial effect on several pathogenic bacteria involved in the pathophysiology of BV, while lactobacilli and the vaginal microenvironment can be positively affected. In contrast to antibiotics, MGH exerts anti-biofilm activity, affects the microbiome as pre- and probiotic, and modulates the vaginal microenvironment through its anti-inflammatory, anti-oxidative, physicochemical, and immunomodulatory properties. More clinical research is required to confirm the positive effect of MGH on BV and to investigate the long-term cure rate.

Optimized bacterial absolute quantification method by qPCR using an exogenous bacterial culture as a normalization strategy in triple-species BV-like biofilms

Quantitative Polymerase Chain Reaction (qPCR) is a widely used method in molecular biology to quantify target DNA sequences. Despite its accuracy, there are important experimental controls that should be considered to avoid biased results. One of them is gDNA loss during extraction, which is higher among samples with lower bacterial concentrations. Improvement in qPCR quantification procedures is mandatory to obtain reproducible and accurate results. Herein, we report an improved qPCR method for bacterial quantification of Gardnerella vaginalis, Prevotella bivia, and Fannyhessea vaginae, three key-bacterial vaginosis (BV)-associated bacteria (BVAB) thought to play important roles in the pathogenesis of this common vaginal infection. The formation of a mature biofilm on vaginal epithelial cells is an unique feature of BV and, despite over 60 years of research, the exact etiology of BV remains unknown. Here, we optimized a qPCR method that accurately quantified triple-species biofilms containing these key BVAB, after the addition of an exogenous bacterial control containing a fixed concentration of Escherichia coli, prior to gDNA extraction. This improved method minimized and normalized the inherent losses associated with bacterial centrifugation, which allows better sensitivity at lower bacterial concentrations.

Inflammatory mediators in bacterial vaginosis: The role of cytokines

BV is a significant concern in women's health with a varying prevalence rate in different cities of China. The condition has been linked to the acquisition of STIs, including HIV and HPV, and can lead to infertility, adverse obstetric outcomes. We conducted a comprehensive literature search in the PubMed. The search was performed from 01/01/2018 to 01/09/2023. The following search terms were used: bacterial vaginosis and cytokine. We also manually searched the reference lists of included studies and relevant reviews to identify additional articles. The presence of Gardnerella spp. can lead to changes in cytokine levels. The immune system of the female reproductive tract consists of various immune cells and molecules that play a vital role in defending against infections. Cytokines, signaling molecules involved in immune cell recruitment and activation, have been identified as potential biomarkers for diagnosing BV and predicting STIs. Current treatments for BV primarily involve antibiotics, but there is a high recurrence rate posttreatment. BV is a complex condition that affects a significant number of women worldwide. The role of cytokines in the onset, progression, and treatment of BV offers promising avenues for future research and potential diagnostic and therapeutic advancements.

Interpretation of vaginal metagenomic characteristics in different types of vaginitis

Although vaginitis is closely related to vaginal microecology in females, the precise composition and functional potential of different types of vaginitis remain unclear. Here, metagenomic sequencing was applied to analyze the vaginal flora in patients with various forms of vaginitis, including cases with a clue cell proportion ranging from 1% to 20% (Clue1_20), bacterial vaginitis (BV), vulvovaginal candidiasis (VVC), and BV combined with VVC (VVC_BV). Our results identified Prevotella as an important biomarker between BV and Clue1_20. Moreover, a gradual decrease was observed in the relative abundance of shikimic acid metabolism associated with bacteria producing indole as well as a decline in the abundance of Gardnerella vaginalis in patients with BV, Clue1_20, and healthy women. Interestingly, the vaginal flora of patients in the VVC_BV group exhibited structural similarities to that of the VVC group, and its potentially functional characteristics resembled those of the BV and VVC groups. Finally, Lactobacillus crispatus was found in high abundance in healthy samples, greatly contributing to the stability of the vaginal environment. For the further study of L. crispatus, we isolated five strains of L. crispatus from healthy samples and evaluated their capacity to inhibit G. vaginalis biofilms and produce lactic acid in vitro to select the potential probiotic candidate for improving vaginitis in future clinical studies. Overall, we successfully identified bacterial biomarkers of different vaginitis and characterized the dynamic shifts in vaginal flora between patients with BV and healthy females. This research advances our understanding and holds great promise in enhancing clinical approaches for the treatment of vaginitis.

IMPORTANCE

Vaginitis is one of the most common gynecological diseases, mostly caused by infections of pathogens such as Candida albicans and Gardnerella vaginalis. In recent years, it has been found that the stability of the vaginal flora plays an important role in vaginitis. Furthermore, the abundant Lactobacillus-producing rich lactic acid in the vagina provides a healthy acidic environment such as Lactobacillus crispatus. The metabolites of Lactobacillus can inhibit the colonization of pathogens. Here, we collected the vaginal samples of patients with bacterial vaginitis (BV), vulvovaginal candidiasis (VVC), and BV combined with VVC to discover the differences and relationships among the different kinds of vaginitis by metagenomic sequencing. Furthermore, because of the importance of L. crispatus in promoting vaginal health, we isolated multiple strains from vaginal samples of healthy females and chose the most promising strain with potential probiotic benefits to provide clinical implications for treatment strategies.

The role of sialidases in the pathogenesis of bacterial vaginosis and their use as a promising pharmacological target in bacterial vaginosis

Bacterial vaginosis (BV) is an infection of the genital tract characterized by disturbance of the normally Lactobacilli-dominated vaginal flora due to the overgrowth of Gardnerella and other anaerobic bacteria. Gardnerella vaginalis, an anaerobic pathogen and the major pathogen of BV, produces sialidases that cleave terminal sialic acid residues off of human glycans. By desialylation, sialidases not only alter the function of sialic acid-containing glycoconjugates but also play a vital role in the attachment, colonization and spread of many other vaginal pathogens. With known pathogenic effects, excellent performance of sialidase-based diagnostic tests, and promising therapeutic potentials of sialidase inhibitors, sialidases could be used as a biomarker of BV. This review explores the sources of sialidases and their role in vaginal dysbiosis, in aims to better understand their participation in the pathogenesis of BV and their value in the diagnosis and treatment of BV.

Microbial interactions among Gardnerella, Prevotella and Fannyhessea prior to incident bacterial vaginosis: protocol for a prospective, observational study

INTRODUCTION

The aetiology of bacterial vaginosis (BV), a biofilm-associated vaginal infection, remains unknown. Epidemiologic data suggest that it is sexually transmitted. BV is characterised by loss of lactic acid-producing lactobacilli and an increase in facultative and strict anaerobic bacteria. Gardnerella spp are present in 95%-100% of cases; Gardnerella vaginalis has been found to be more virulent than other BV-associated bacteria (BVAB) in vitro. However, G. vaginalis is found in women with normal vaginal microbiota and colonisation is not sufficient for BV development. We hypothesise that Gardnerella spp initiate BV biofilm formation, but incident BV (iBV) requires incorporation of other key BVAB (ie, Prevotella bivia, Fannyhessea vaginae) into the biofilm that alter the transcriptome of the polymicrobial consortium. This study will investigate the sequence of microbiologic events preceding iBV.

METHODS AND ANALYSIS

This study will enrol 150 women aged 18-45 years with normal vaginal microbiota and no sexually transmitted infections at a sexual health research clinic in Birmingham, Alabama. Women will self-collect twice daily vaginal specimens up to 60 days. A combination of 16S rRNA gene sequencing, qPCR for Gardnerella spp, P. bivia and F. vaginae, and broad range 16S rRNA gene qPCR will be performed on twice daily vaginal specimens from women with iBV (Nugent score 7-10 on at least 2 consecutive days) and controls (with comparable age, race, contraceptive method and menstrual cycle days) maintaining normal vaginal microbiota to investigate changes in the vaginal microbiota over time for women with iBV. Participants will complete daily diaries on multiple factors including sexual activity.

ETHICS AND DISSEMINATION

This protocol is approved by the University of Alabama at Birmingham Institutional Review Board (IRB-300004547) and written informed consent will be obtained from all participants. Findings will be presented at scientific conferences and published in peer-reviewed journals as well as disseminated to providers and patients in communities of interest.

Bacterial Vaginosis and Vulvovaginal Candidiasis Pathophysiologic Interrelationship

Among the infectious causes of vulvovaginal symptoms, bacterial vaginosis (BV) and vulvovaginal candidiasis (VVC) dominate. Apart from infrequent mixed infections, both are considered independent and caused by unrelated pathogenic mechanisms. Clinical experience, however, is strongly suggestive that in some populations these infections are linked with recurrent BV (RBV) serving as the dominant etiopathogenic trigger for development of recurrent VVC (RVVC) with profound clinical and therapeutic consequences. The biologic basis for this critical interrelationship is discussed and suggests that as a consequence of BV dysbiosis, and not necessarily because of antibiotics prescribed, immune defenses are compromised, neutralizing vaginal yeast tolerance. The consequent BV-induced vaginal proinflammatory environment predisposes to mixed infection or consecutive episodes of post-treatment VVC. Recurrent BV and repeated antimicrobial drug exposure also predispose to acquired fluconazole resistance in C. albicans isolates, contributing to refractory vulvovaginal candidiasis.

Molecular Testing for the Diagnosis of Bacterial Vaginosis

Previously established diagnostic approaches for the diagnosis of bacterial vaginosis (BV), such as the Amsel criteria or the Nugent scoring system, do not always correspond to modern trends in understanding the etiology and pathogenesis of polymicrobial conditions. Inter-examiner variability and interpretation of data complicate the wet mount microscopy method. Gram staining of smears does not always provide reliable information regarding bacterial taxa, biofilms, or vaginal dysbiosis. Therefore, the introduction of molecular techniques into clinical practice is extremely relevant. Molecular approaches allow not only the diagnosis of BV but also provide an assessment of microbial composition, which is especially important in the differential diagnosis of vaginal infections. The current review represents an expert opinion on BV diagnosis and is based on extensive experience in the field of vaginal infection diagnosis and treatment.

Resident microbes shape the vaginal epithelial glycan landscape

Epithelial cells are covered in carbohydrates (glycans). This glycan coat or "glycocalyx" interfaces directly with microbes, providing a protective barrier against potential pathogens. Bacterial vaginosis (BV) is a condition associated with adverse health outcomes in which bacteria reside in direct proximity to the vaginal epithelium. Some of these bacteria, including Gardnerella, produce glycosyl hydrolase enzymes. However, glycans of the human vaginal epithelial surface have not been studied in detail. Here, we elucidate key characteristics of the "normal" vaginal epithelial glycan landscape and analyze the impact of resident microbes on the surface glycocalyx. In human BV, glycocalyx staining was visibly diminished in electron micrographs compared to controls. Biochemical and mass spectrometric analysis showed that, compared to normal vaginal epithelial cells, BV cells were depleted of sialylated N- and O-glycans, with underlying galactose residues exposed on the surface. Treatment of primary epithelial cells from BV-negative women with recombinant Gardnerella sialidases generated BV-like glycan phenotypes. Exposure of cultured VK2 vaginal epithelial cells to recombinant Gardnerella sialidase led to desialylation of glycans and induction of pathways regulating cell death, differentiation, and inflammatory responses. These data provide evidence that vaginal epithelial cells exhibit an altered glycan landscape in BV and suggest that BV-associated glycosidic enzymes may lead to changes in epithelial gene transcription that promote cell turnover and regulate responses toward the resident microbiome.

Analyses of the Chemical Composition of Plasma-Activated Water and Its Potential Applications for Vaginal Health

This study aimed to elucidate the unique chemical compositions of plasma-activated water (PAW) and the potential antibacterial efficacy of PAW as a novel vaginal cleanser. We analyzed the ion compositions (four anions: F-, Cl-, NO3-, SO42-; five cations: Na+, NH4+, K+, Mg2+, Ca2+) of several formulations of PAW generated at different electrical powers (12 and 24 V) at various treatment time points (1, 10, and 20 min), and stay durations (immediate, 30, and 60 min). As treatment duration increased, hypochlorous acid (HOCl), Ca2+, and Mg2+ concentrations increased and Cl- concentration decreased. Higher electrical power and longer treatment duration resulted in increased HOCl levels, which acts to prevent the growth of general microorganisms. Notably, PAW had no antibacterial effects against the probiotic, Lactobacillus reuteri, which produces lactic acid and is important for vaginal health. These findings indicate that PAW contains HOCl and some cations (Ca2+ and Mg2+), which should help protect against pathogens of the vaginal mucosa and have a cleansing effect within the vaginal environment while not harming beneficial bacteria.

Vaginal microecology and its role in human papillomavirus infection and human papillomavirus associated cervical lesions

The vaginal microecology comprises the vaginal microbiome, immune microenvironment, vaginal anatomy, and the cervicovaginal fluid, which is rich in metabolites, enzymes, and cytokines. Investigating its role in the female reproductive system holds paramount significance. The advent of next-generation sequencing enabled a more profound investigation into the structure of the vaginal microbial community in relation to the female reproductive system. Human papillomavirus infection is prevalent among women of reproductive age, and persistent oncogenic HPV infection is widely recognized as a factor associated with cervical cancer. Extensive previous research has demonstrated that dysbiosis of vaginal microbiota characterized by a reduction in Lactobacillus species, heightens susceptivity to HPV infection, consequently contributing to persistent HPV infection and the progression of cervical lesion. Likewise, HPV infection can exacerbate dysbiosis. This review aims to provide a comprehensive summary of current literatures and to elucidate potential mechanisms underlying the interaction between vaginal microecology and HPV infection, with the intention of offering valuable insights for future clinical interventions.

Gardnerella pickettii sp. nov. (formerly Gardnerella genomic species 3) and Gardnerella greenwoodii sp. nov. (formerly Gardnerella genomic species 8) isolated from female urinary microbiome

During an ongoing female urinary microbiome research study, strains c17Ua_112T and c31Ua_26T isolated from urine samples of a patient diagnosed with overactive bladder and a healthy postmenopausal woman, respectively, could not be allocated to any Gardnerella species with valid names. In this work, we aimed to characterize these strains. The 16S rRNA gene sequences confirmed that these strains are members of the genus Gardnerella. Phylogenetic analysis based on cpn60 strongly supported two clades, one encompassing c17Ua_112T and nine other strains from the public database, and the other including c31Ua_26T and three other strains, which were distinct from currently recognized species of the genus Gardnerella. Likewise, the phylogenomic tree also showed that strains c17Ua_112T and c31Ua_26T formed independent and robust clusters. Average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values between c17Ua_112T and c31Ua_26T were 79.27 and 27.4 %, respectively. Strain c17Ua_112T showed the highest ANI (94.8 %) and dDDH values (59.8 %) with Gardnerella piotii UGent 18.01T, and strain c31Ua_26T revealed highest ANI (84.2 %) and dDDH (29.1 %) values with Gardnerella swidsinskii GS 9838-1T. Based on the data presented here, the two strains c17Ua_112T and c31Ua_26T represent two novel species of the genus Gardnerella, for which the names Gardnerella pickettii (c17Ua_112T=DSM 113414T=CCP 71T) and Gardnerella greenwoodii (c31Ua_26T=DSM 113415T=CCP 72T) are proposed.

Bacterial Vaginosis: Guideline of the DGGG, OEGGG and SGGG (S2k-Level, AWMF Registry No. 015/028, June 2023)

Aim This official guideline was coordinated and published by the DGGG, OEGGG and SGGG with the involvement of additional professional societies. The aim of the guideline is to evaluate the relevant literature and use it to provide a consensus-based overview of the diagnosis and management of bacterial vaginosis. Methods This S2k-guideline was developed by representative members from different medical professional societies on behalf of the guidelines commission of the above-listed societies using a structured consensus process. Recommendations This guideline provides recommendations on the diagnosis, management, counselling, prophylaxis, and other aspects related to bacterial vaginosis.

Prevotella and Gardnerella Are Associated With Treatment Failure Following First-line Antibiotics for Bacterial Vaginosis

BACKGROUND

Bacterial vaginosis (BV) is a common vaginal dysbiosis that often recurs following first-line antibiotics. We investigated if vaginal microbiota composition was associated with BV recurrence.

METHODS

We analyzed samples and data from 121 women who participated in 3 published trials evaluating novel interventions for improving BV cure, including concurrent antibiotic treatment of regular sexual partners (RSPs). Women diagnosed with BV received first-line antibiotics and self-collected vaginal swabs pretreatment and the day after finishing antibiotics (immediately posttreatment). 16S rRNA gene sequencing was performed on vaginal samples. Logistic regression explored associations between BV recurrence and features of the vaginal microbiota pre- and posttreatment.

RESULTS

Sixteen women (13% [95% confidence interval {CI}, 8%-21%]) experienced BV recurrence within 1 month of treatment. Women with an untreated RSP were more likely to experience recurrence than women with no RSP (P = .008) or an RSP who received treatment (P = .011). A higher abundance of Prevotella pretreatment (adjusted odds ratio [AOR], 1.35 [95% CI, 1.05-1.91]) and Gardnerella immediately posttreatment (AOR, 1.23 [95% CI, 1.03-1.49]) were associated with increased odds of BV recurrence.

CONCLUSIONS

Having specific Prevotella spp prior to recommended treatment and persistence of Gardnerella immediately posttreatment may contribute to the high rates of BV recurrence. Interventions that target these taxa are likely required to achieve sustained BV cure.

Cervicovaginal Gardnerella sialidase-encoding gene in persistent human papillomavirus infection

Disturbed vaginal microbiota have a role in the persistence of high-oncogenic-risk human papillomavirus (hrHPV) and Gardnerella spp. is closely related with this condition. Such bacteria are the major source of cervicovaginal sialidases, important for microbiota alterations. The sialidase-encoding gene nanH3 is account for their sialidase activity. Thus, a subset of 212 women positive for hrHPV at the first visit were included in the analysis of the current study aiming to compare the loads of nanH3 in cervicovaginal fluid (CFV) of women with persistent hrHPV infection and with those cleared the infection after a year. Participants were assigned to two study groups named "persistence" (n = 124, 53.22%) or "clearance" (n = 88, 37.77%), according to the HPV status upon enrollment and follow-up. Absolute quantification of nanH3 gene was performed using quantitative real-time PCR (qPCR). Persistence and clearance group did not show statistical difference in the load of nanH3 gene (p = 0.19). When considering the subset of women with HPV16, differences in number of copies of nanh3 gene was observed between the persistent (7.39E+08 copies/μL) and clearance group (2.85E+07 copies/μL) (p = 0.007). Therefore, baseline loads of nanH3 gene is increased in women that persist with cervical HPV16 infection after 12 months.

Biofilm-Forming Capacity and Drug Resistance of Different Gardnerella Subgroups Associated with Bacterial Vaginosis

Bacterial vaginosis (BV) is the most common infection of the lower reproductive tract among women of reproductive age. Recurrent infections and antibiotic resistance associated with biofilms remain significant challenges for BV treatment. Gardnerella species are commonly found in women with and without BV, indicating that genetic differences among Gardnerella isolates may distinguish pathogenic from commensal subgroups. This study isolated 11 Gardnerella strains from vaginal samples obtained from women with BV before or after treatment. The biofilm formation ability of each strain was examined by crystal violet staining. Eight strains were selected using phylogenetic analysis of the cpn60 sequences and classified as subgroups A (6/8), B (1/8), and D (1/8). The biofilm formation ability and antibiotic resistance profile of these strains was compared among the subgroups. Subgroup D had the strongest biofilm formation ability. Six of the planktonic strains exhibited resistance to the first-line BV drug, metronidazole, and one to clindamycin. Moreover, biofilm formation in vitro increased strain resistance to clindamycin. Two strains with strong biofilm ability, S20 and S23, and two with weak biofilm ability, S24 and S25, were selected for comparative genomic analysis. S20 and S23 were found to contain four key genes associated with biofilm formation and more genes involved in carbohydrate synthesis and metabolism than S24 and S25. Identifying differences in the expression of virulence factors between Gardnerella subgroups could inform the development of novel treatments for BV.

Bacterial biofilms in the human body: prevalence and impacts on health and disease

Bacterial biofilms can be found in most environments on our planet, and the human body is no exception. Consisting of microbial cells encased in a matrix of extracellular polymers, biofilms enable bacteria to sequester themselves in favorable niches, while also increasing their ability to resist numerous stresses and survive under hostile circumstances. In recent decades, biofilms have increasingly been recognized as a major contributor to the pathogenesis of chronic infections. However, biofilms also occur in or on certain tissues in healthy individuals, and their constituent species are not restricted to canonical pathogens. In this review, we discuss the evidence for where, when, and what types of biofilms occur in the human body, as well as the diverse ways in which they can impact host health under homeostatic and dysbiotic states.

State of the Art for Diagnosis of Bacterial Vaginosis

Bacterial vaginosis (BV) is the most common cause of vaginal discharge among reproductive-age women. It is associated with multiple adverse health outcomes, including increased risk of acquisition of HIV and other sexually transmitted infections (STIs), in addition to adverse birth outcomes. While it is known that BV is a vaginal dysbiosis characterized by a shift in the vaginal microbiota from protective Lactobacillus species to an increase in facultative and strict anaerobic bacteria, its exact etiology remains unknown. The purpose of this minireview is to provide an updated overview of the range of tests currently used for the diagnosis of BV in both clinical and research settings. This article is divided into two primary sections: traditional BV diagnostics and molecular diagnostics. Molecular diagnostic assays, particularly 16S rRNA gene sequencing, shotgun metagenomic sequencing, and fluorescence in situ hybridization (FISH), are specifically highlighted, in addition to multiplex nucleic acid amplification tests (NAATs), given their increasing use in clinical practice (NAATs) and research studies (16S rRNA gene sequencing, shotgun metagenomic sequencing, and FISH) regarding the vaginal microbiota and BV pathogenesis. We also provide a discussion of the strengths and weaknesses of current BV diagnostic tests and discuss future challenges in this field of research.

Understanding and Preventing Recurring Bacterial Vaginosis: Important Considerations for Clinicians

Bacterial vaginosis (BV) is the most common vaginal infection worldwide. It is associated with an increased risk of acquisition of HIV and other sexually transmitted infections (STIs) as well as pelvic inflammatory disease and adverse birth outcomes. During BV, a polymicrobial biofilm forms on the surface of the vaginal mucosa. However, the exact etiology of BV remains controversial which has impeded significant advances in diagnosis, treatment, and prevention. Despite 30-day cure rates approaching 80% in BV-infected women treated with 7 days of oral metronidazole, recurrence within 12 months is common. This article provides a current review of the epidemiology, pathogenesis, diagnosis, and treatment of recurrent BV for practicing clinicians who commonly see women with this recurrent vaginal infection. Regarding management, we focus primarily on antimicrobial measures that may be effective. Future areas of research in this field are also discussed.

Mycobiome Study Reveals Different Pathogens of Vulvovaginal Candidiasis Shape Characteristic Vaginal Bacteriome

Vulvovaginal candidiasis (VVC) can alter the vaginal microbiome composition and structure, and this may be correlated with its variable treatment efficacy. Integrated analysis of the mycobiome and bacteriome in VVC could facilitate accurate diagnosis of infected patients and further decipher the characterized bacteriome in different types of VVC. Our mycobiome analysis determined two common types of VVC, which were clustered into two community state types (CSTs) featured by Candida glabrata (CST I) and Candida albicans (CST II). Subsequently, we compared the vaginal bacteriome in two CSTs of VVC and two other types of reproductive tract infections (RTIs), bacterial vaginosis (BV) and Ureaplasma urealyticum (UU) infection. The vaginal bacteriome in VVC patients was between the healthy and other RTIs (BV and UU) status, it bore the greatest resemblance to that of healthy subjects. While BV and UU patients have the unique vaginal microbiota community structure, which very different with healthy women. Compared with CST II, the vaginal bacteriome of CST I VVC was characterized by Prevotella, a key signature in BV. In comparison, CST II was featured by Ureaplasma, the pathogen of UU. The findings of our study highlight the need for co-analysis and simultaneous consideration of vaginal mycobiome and bacteriome in the diagnosis and treatment of VVC to solve common clinical problems, such as unsatisfactory cure rates and recurrent symptoms. IMPORTANCE Fungi headed by C. albicans play a critical role in VVC but are not sufficient for its occurrence, indicating the involvement of other factors, such as the vaginal bacteriome. We found that different CST correspond to different bacterial composition in patients with VVC, and this could underlie the alteration of vaginal microorganism environment in VVC patients. We believe that this correlation should not be ignored, and it may be related to the unsatisfactory treatment outcomes and high recurrence rate of VVC. Here, we provided evidence for associations between vaginal bacteriome patterns and fungal infection. Screening specific biomarkers for three common RTIs paves a theoretical basis for further development of personalized precision treatment.

Bacterial vaginosis: a review of approaches to treatment and prevention

Bacterial vaginosis (BV) is a common cause of vaginitis worldwide and is associated with serious reproductive health outcomes, including increased risk of preterm birth, sexually transmitted infections, and pelvic inflammatory disease. The current and only FDA-approved treatment regimens for BV are antibiotics, such as metronidazole and clindamycin. Antibiotics provide a short-term cure for bacterial vaginosis; however, fail to provide a consistent long-term cure for many women. Fifty to eighty percent of women experience a BV recurrence within a year of completing antibiotic treatment. This may be because after antibiotic treatment, beneficial strains of Lactobacillus, such as L. crispatus, do not recolonize the vagina. In the absence of an effective long-term cure, patients, providers, and researchers are exploring different approaches to treatment and prevention, resulting in a rapid evolution of perspectives on BV pathogenesis and approaches to management. Current areas of investigation for BV management include probiotics, vaginal microbiome transplantation, pH modulation, and biofilm disruption. Behavioral modifications that may help include smoking cessation, condom use and hormonal contraception. Additional strategies considered by many people include dietary modification, non-medical vaginally applied products, choice of lubricant, and treatments from medical practices outside of allopathic medicine. This review aims to provide a comprehensive and up to date outline of the landscape of ongoing and potential treatment and prevention strategies for BV.

Bacterial Vaginosis-Vaginal Polymicrobial Biofilms and Dysbiosis

BACKGROUND

Bacterial vaginosis (BV) is the most common genital disease worldwide in women of sexually active age, with a prevalence of 23-29%. Its traditional definition as dysbiosis, i.e., a disruption of the normal balance of the vaginal microbiota, with a massive increase of facultative and obligate anaerobic bacteria (mainly Gardnerella spp.) and a loss of lactobacilli, accurately describes the change in the vaginal microbiota, but does not explain the underlying pathophysiology.

METHODS

This review is based on information in pertinent articles retrieved by a selective literature search and on the authors' own research findings.

RESULTS

Fluorescent in situ hybridization (FISH) has revealed Gardnerella spp.-dominated polymicrobial vaginal biofilm as a cause of ascending gynecologic and pregnancy-related infections, preterm birth, and infertility in patients with BV. The biofilm-induced disturbance of epithelial homeostasis favors co-infection with pathogens of sexually transmitted infection (STI). Standard antibiotic therapy is ineffective against biofilms, and there is thus a recurrence rate above 50%. The characteristic biofilm can be followed as a diagnostic marker and is considered evidence of sexual transmission when heterosexual couples and ejaculate samples are examined. FISH studies have shown that, in addition to biofilm-related vaginosis, there are other dysbiotic changes in the vaginal microbiota that have not yet been characterized in detail. It is therefore justified to speak of a "bacterial vaginosis syndrome."

CONCLUSION

The simplistic view of BV as dysbiosis, characterizable by microscopic reference methods, has so far led to inadequate therapeutic success. An evaluation of molecular genetic testing methods that would be suitable for routine use and the development of therapeutic agents that are effective against biofilms are urgently needed if the "bacterial vaginosis syndrome" is to be effectively treated.

Bacterial Vaginosis and Post-Operative Pelvic Infections

Bacterial vaginosis (BV) represents a condition in which the normal protective Lactobacilli, especially those that produce H₂O₂, are replaced by high quantities of facultative anaerobes, leading to gynecologic and obstetric post-operative complications. BV is an important cause of obstetric and gynecological adverse sequelae and it could lead to an increased risk of contracting sexually transmitted infections such as gonorrhea, genital herpes, Chlamydia, Trichomonas, and human immunodeficiency virus. Herein, we reviewed bacterial vaginosis and its association with post-operative pelvic infections. In Obstetrics, BV has been associated with increased risk of preterm delivery, first-trimester miscarriage in women undergoing in vitro fertilization, preterm premature rupture of membranes, chorioamnionitis, amniotic fluid infections, postpartum and postabortal endomyometritis as well as postabortal pelvic inflammatory disease (PID). In gynecology, BV increases the risk of post-hysterectomy infections such as vaginal cuff cellulitis, pelvic cellulitis, pelvic abscess, and PID. BV is often asymptomatic, can resolve spontaneously, and often relapses with or without treatment. The American College of Obstetricians and Gynecologists recommends testing for BV in women having an increased risk for preterm delivery. Women with symptoms should be evaluated and treated. Women with BV undergoing gynecological surgeries must be treated to reduce the frequency of post-operative pelvic infections. Metronidazole and clindamycin are the mainstays of therapy. Currently, there is no consensus on pre-surgery screening for BV; decisions are made on a case-by-case basis.

Impact of (recurrent) bacterial vaginosis on quality of life and the need for accessible alternative treatments

BACKGROUND

Bacterial vaginosis (BV) is one of the most common vaginal dysbiosis in women aged 15-44 years old.

METHODS

We administered a cross-sectional, single timepoint survey to women ages 18 years or older and who have had bacterial vaginosis (BV). Women completed an anonymous online survey evaluating the impact of BV on their quality of life, how effective different types of treatments were and the amount of self-diagnosed vs. provider diagnosed BV episodes they had.

RESULTS

62 participants completed the anonymous online survey. With a self-reported median number of BV episodes in the past year was 4 (IQR 1-7). Among these women 69.8% reported BV had a negative impact on their sexual health, 67.7% on their physical health, 74.6% on their mental health. More than half of the respondents had used probiotics with oral Lactobacillus sp. (53.2%), mainly by oral route, and over a third had used vaginal boric acid (37.1%). Most women were unaware of Lactobacillus crispatus. Lactobacillus probiotics were more likely to be tried by women who were negatively impacted by BV for overall quality of life (p = 0.033), sexual health (p = 0.002), and mental health (p = 0.006) while boric acid use was more likely to be used by women who were negatively impacted by BV for their sexual health (p = 0.008).

CONCLUSIONS

BV is associated with negative quality of life and the women most impacted are seeking alternative treatments such as probiotics (Lactobacillus) and boric acid. There needs to be improvements in BV treatment that include alternative therapy options that have demonstrated efficacy with standardized composition, formulation and dosage.

Inflammatory invasion on human vaginal mucosa correlated with combined drug treatment and recurrence in recurrent vulvovaginal candidiasis

AIM

Recurrent vulvovaginal candidiasis (RVVC) is a chronic, difficult to treat vaginal infection, caused by Candida species, which affects women of all ages and ethnic and social background. Most RVVC studies use animal models, and there is still a lack of observation on human tissue samples and effective therapy to reduce recurrence.

MATERIALS AND METHODS

We observed CD163⁺ macrophages and NLRP3 expression by immunohistochemistry, also investigated bacteria and fungi co-invasion by fluorescence in situ hybridization from 144 human vaginal biopsy tissues (48 RVVC, 48 VVC, 48 healthy volunteers), and we also explored the effect of combining metronidazole in the treatment of RVVC.

RESULTS

A large number of neutrophils, lymphocytes and plasma cells infiltrated the mucosa, basement membrane and submucosa, accompanied by significantly overexpressed NLRP3 inflammasome. While CD163⁺ macrophages often infiltrated under the basement membrane in patients with RVVC, 29.2% of cases were found Gardnerella and fungi jointly invaded the vaginal mucosas. RVVC vaginal mucosal histopathology revealed mucosal inflammatory responses dominated by neutrophils, which may involve activation of NLRP3 and immune tolerance of M2 macrophages (CD163⁺ ). Fluconazole combined with metronidazole can achieve higher efficiency (95.8% vs. 70.8%) and reduce the recurrence rate more (8.3% vs. 37.5%) at 6-month follow-up.

CONCLUSION

Inflammatory invasion on human vaginal mucosa correlated with combined drug treatment and recurrence in RVVC. The combined medication will need to further evaluate in future.

Ureaplasma parvum infection induces inflammatory changes in vaginal epithelial cells independent of sialidase

BACKGROUND

Ureaplasma, a genus of the order Mycoplasmatales and commonly grouped with Mycoplasma as genital mycoplasma is one of the most common microbes isolated from women with infection/inflammation-associated preterm labor (PTL). Mycoplasma spp. produce sialidase that cleaves sialic acid from glycans of vaginal mucous membranes and facilitates adherence and invasion of the epithelium by pathobionts, and dysregulated immune response. However, whether Ureaplasma species can induce the production of sialidase is yet to be demonstrated. We examined U. parvum-infected vaginal epithelial cells (VECs) for the production of sialidase and pro-inflammatory cytokines.

METHODS

Immortalized VECs were cultured in appropriate media and treated with U. parvum in a concentration of 1 × 10⁵ DNA copies/ml. After 24 h of treatment, cells and media were harvested. To confirm infection and cell uptake, immunocytochemistry for multi-banded antigen (MBA) was performed. Pro-inflammatory cytokine production and protein analysis for sialidase confirmed pro-labor pathways.

RESULTS

Infection of VECs was confirmed by the presence of intracellular MBA. Western blot analysis showed no significant increase in sialidase expression from U. parvum-treated VECs compared to uninfected cells. However, U. parvum infection induced 2-3-fold increased production of GM-CSF (p = 0.03), IL-6 (p = 0.01), and IL-8 (p = 0.01) in VECs compared to controls.

CONCLUSION

U. parvum infection of VECs induced inflammatory imbalance associated with vaginal dysbiosis but did not alter sialidase expression at the cellular level. These data suggest that U. parvum's pathogenic effect could be propagated by locally produced pro-inflammatory cytokines and, unlike other genital mycoplasmas, may be independent of sialidase.

Therapeutic effects of fenticonazole on bacterial vaginosis in mice

Bacterial vaginitis (BV) is a syndrome of increased vaginal discharge, fishy smelling leucorrhea, and itching and burning vulva caused by the microecological imbalance in the vagina induced by mixture of Gardnerella vaginalis (GV) and some anaerobic bacteria. Fenticonazole, an imidazole derivative and antimicrobial compound, has been demonstrated to exert effective therapeutic effects in mixed vaginitis. Accordingly, our study was designed to explore the potential role of fenticonazole in GV-infected BV mouse models. Female C57/BL6 mice were injected intraperitoneally with β-estradiol 3 days before and on the day of GV infection to maintain a pseudoestrus state. On the day of infection, mice were intravaginally inoculated with 20 µl of a suspension of GV (6 × 106 CFU/ml). Fenticonazole was administered as 2% vaginal cream (0.2 mg each mouse) by intravaginal application once a day for 3 days beginning the day of infection. At day 3 postinfection, the mice were sacrificed and vaginal washes were harvested. GV proliferation and Lactobacillus content were calculated in the vaginal lavage. Neutrophil counts in the vaginal lavage were observed through Pap staining. Myeloperoxidase (MPO) activity and proinflammatory cytokine (TNF-α, IL-1β, IL-6, iNOS, COX2, and NF-κB) levels in vaginal tissues were measured by ELISA and western blotting. Vaginal tissues were stained by hematoxylin and eosin (H&E) to examine the exfoliation of vaginal epithelial cells. GV infection increased GV proliferation and neutrophil counts but reduced Lactobacillus content in the vaginal lavage, as well as enhanced MPO activity, proinflammatory cytokine levels, and the exfoliation of vaginal epithelial cells in vaginal tissues of BV mouse models. However, administration of fenticonazole significantly ameliorated the above phenomena. Fenticonazole greatly improves the symptoms of GV-induced BV in mouse models.

HEALTHCARE-ASSOCIATED BACTERIAL VAGINOSIS AFTER GYNECOLOGICAL SURGERIES AND ASSOCIATED ADVERSE PREGNANCY OUTCOME IN UKRAINE

OBJECTIVE

The aim: To determine the prevalence of healthcare-associated bacterial vaginosis after gynecological surgeries and associated adverse pregnancy outcomes in Ukraine.

PATIENTS AND METHODS

Materials and methods: Multicenter retrospective cohort study was conducted from January 2019 to December 2021 in eleven medical centers from eight regions of Ukraine. Vaginal cultures were obtained preoperatively from 3,502 women undergoing gynecologic surgery. Diagnosis of Bacterial Vaginosis is based on the Nugent and Amsel criteria.

RESULTS

Results: Healthcare-associated bacterial vaginosis (HA BV) was diagnosed in 1,498 of 3,502 women, giving a prevalence rate of 42.8%. HA BV was significantly associated with preterm birth (risk ratio [RR], 2.68; 95% confidence interval [CI], 1.44-4.98), miscarriage (RR, 6.11; 95% CI, 3.22-14.11), low birth weight (RR, 3.20; 95% CI, 1.29-7.94), and premature rupture of membranes (RR, 6.75; 95% CI, 3.11-14.67).

CONCLUSION

Conclusions: The HA BV after gynecological surgeries prevalence is high in Ukraine, with a concomitant adverse pregnancy outcome, including preterm birth, low birth weight, premature rupture of membranes, and miscarriage. A significant number of cases of bacterial vaginosis are associated with long-term use of antibiotics to treat post-operative infections.

Immunometabolic and potential tumor-promoting changes in 3D cervical cell models infected with bacterial vaginosis-associated bacteria

Specific bacteria of the human microbiome influence carcinogenesis at diverse anatomical sites. Bacterial vaginosis (BV) is the most common vaginal disorder in premenopausal women that is associated with gynecologic sequelae, including cervical cancer. BV-associated microorganisms, such as Fusobacterium, Lancefieldella, Peptoniphilus, and Porphyromonas have been associated with gynecologic and other cancers, though the pro-oncogenic mechanisms employed by these bacteria are poorly understood. Here, we integrated a multi-omics approach with our three-dimensional (3-D) cervical epithelial cell culture model to investigate how understudied BV-associated bacteria linked to gynecologic neoplasia influence hallmarks of cancer in vitro. Lancefieldella parvulum and Peptoniphilus lacrimalis elicited robust proinflammatory responses in 3-D cervical cells. Fusobacterium nucleatum and Fusobacterium gonidiaformans modulated metabolic hallmarks of cancer corresponding to accumulation of 2-hydroxyglutarate, pro-inflammatory lipids, and signs of oxidative stress and genotoxic hydrogen sulfide. This study provides mechanistic insights into how gynecologic cancer-associated bacteria might facilitate a tumor-promoting microenvironment in the human cervix.

Gardnerella Vaginalis Dominates Multi-Species Biofilms in both Pre-Conditioned and Competitive In Vitro Biofilm Formation Models

Bacterial vaginosis (BV) is one of the most common bacterial vaginal infections worldwide. Despite its high prevalence, BV etiology is still unknown. Nevertheless, a hallmark of BV is the presence of a highly structured polymicrobial biofilm on the vaginal epithelium, formed primarily by Gardnerella spp. and other anaerobic species, of which co-colonization with Fannyhessea vaginae is considered an important diagnostic marker. We previously developed an in vitro biofilm model wherein Gardnerella was first allowed to establish an early biofilm that served as a scaffold for other species to adhere to. To better understand ecological interactions between BV-associated bacteria, we compared triple-species biofilms formed using two distinct models: a pre-conditioned (wherein Gardnerella vaginalis formed the early biofilm) model and a competitive (wherein all three bacteria were co-incubated together) model. Interestingly, synergistic growth interactions were more significant in the competitive model. Furthermore, the biofilm structure and species-specific distribution, as assessed by confocal laser scanning microscopy and using peptide nucleic acid fluorescence in situ hybridization method, revealed two very different triple-species morphotypes, suggesting that different interactions occur in the different models. Interestingly, independent of the model or triple-species consortium tested, we observed that G. vaginalis represented most of the biofilm bacterial composition, further highlighting the relevance of this taxon in BV.

Antibiotic resistance and pathogenicity assessment of various Gardnerella sp. strains in local China

Gardnerella overgrowth is the primary cause of bacterial vaginosis (BV), a common vaginal infection with incidences as high as 23–29% worldwide. Here, we studied the pathogenicity, drug resistance, and prevalence of varying Gardnerella spp. We isolated 20 Gardnerella strains from vaginal samples of 31 women in local China. Ten strains were then selected via phylogenetic analysis of cpn60 and vly gene sequences to carry out genome sequencing and comparative genomic analysis. Biofilm-formation, sialidase, and antibiotic resistance activities of the strains were characterized. All strains showed striking heterogeneity in genomic structure, biofilm formation and drug resistance. Two of the ten strains, JNFY3 and JNFY15, were classified as Gardnerella swidsinskii and Gardnerella piotii, respectively, according to their phenotypic characteristics and genome sequences. In particular, seven out of the ten strains exhibited super resistance (≥ 128 μg/mL) to metronidazole, which is the first line of treatment for BV in China. Based on the biochemical and genomic results of the strains, we proposed a treatment protocol of prevalent Gardnerella strains in local China, which provides the basis for accurate diagnosis and therapy.

Antimicrobial activity of bovine lactoferrin against Gardnerella species clinical isolates

Gardnerella species play a key role in the development and recurrence of Bacterial Vaginosis (BV), a common imbalance of the vaginal microbiota. Because of the high rates of BV recurrence reported after treatment with standard of care antibiotics, as well as the emergence of antibiotic-resistant BV, the development of alternative treatment approaches is needed. Bovine lactoferrin, a well studied iron-binding glycoprotein with selective antimicrobial activity, may ameliorate vaginal dysbiosis either alone or in combination with antibiotics. The present study evaluated the antimicrobial resistance/susceptibility profile of seventy-one presumptive G. vaginalis clinical isolates to metronidazole and clindamycin. In addition, the in vitro antimicrobial activity of Metrodora Therapeutics bovine Lactoferrin (MTbLF) against the tested clinical isolates, both alone and in combination with metronidazole and clindamycin, was in depth evaluated using defined-iron culture conditions. All 71 presumptive G. vaginalis clinical isolates exhibited resistance to metronidazole, with MIC values greater than 256 μg/ml. Different susceptibility profiles were detected for clindamycin. In detail, the vast majority of the tested strains (45%), exhibiting MIC lower than 2 μg/ml, were considered sensitive; 18 strains (25%) with MIC higher or equal to 8 μg/ml, were classified as resistant, whereas the remaining 21 (30%) were classified as intermediate. MTbLF was tested in culture medium at different concentrations (32, 16, 8, 4, 2, 1, and 0.5 mg/ml) showing ability to inhibit the growth of the tested presumptive G. vaginalis clinical isolates, including those metronidazole-resistant, in a dose-dependent and not in a strain-dependent manner. MTbLF, at concentrations ranging from 32 to 8 mg/ml, exerted a statistically different antimicrobial activity compared with lower concentrations (4, 2, 1, and 0.5 mg/ml). A synergistic effect between MTbLF (8 and 4 mg/ml) and clindamycin was revealed for all the tested strains. When tested in the absence of other sources of iron, MTbLF did not support the growth of the tested presumptive G. vaginalis clinical isolates. Bovine lactoferrin may be a potential candidate to treat Gardnerella species infection.

Antagonistic activity of Lactiplantibacillus plantarum 6.2 extracted from cocoa fermentation and its supernatant on Gardnerella vaginalis

Search for alternative methods for the treatment of bacterial vaginosis has been growing, and probiotics being among them. The most well-known probiotic microorganisms are lactobacilli, which are naturally present in the vaginal microenvironment. Cocoa fermentation is a source of lactic acid bacteria, with lactobacilli being the most prominent. The aim of this study was to evaluate the antagonistic activity of Lactiplantibacillus plantarum 6.2 a strain of lactobacilli isolated from cocoa fermentation, and its cell-free supernatant on Gardnerella vaginalis. It was shown that Lpb. plantarum 6.2 and its supernatant, used at three concentrations, i.e., 40, 20 and 10 mg/mL, have a strong antagonistic activity against G. vaginalis, with a probable action of proteinaceous bacteriocins; the activity was lost after heat treatment. The ability to exclude and displace G. vaginalis from the adhesion site to vaginal HMVII epithelial cells was also demonstrated by the lactobacilli and the supernatant, with the latter showing a bactericidal effect. Thus, the Lpb. plantarum 6.2 strain presents itself as a good probiotic with potential to be used not only as a therapeutic alternative for vaginosis but also as a complement to existing therapies.

Association of key species of vaginal bacteria of recurrent bacterial vaginosis patients before and after oral metronidazole therapy with short- and long-term clinical outcomes

Bacterial vaginosis (BV) is associated with a state of vaginal dysbiosis typically involving depletion of otherwise dominant populations of Lactobacillus. The causes of this microbial succession are not known; there may be multiple causes. Standard treatment includes oral metronidazole, which typically restores Lactobacillus species to dominance. However, recurrence rates are high; recurrent BV patients recur 3–4 times annually and are often refractory to treatment. Our previous qPCR-based study of recurrent BV patients pointed to putatively more virulent species of Gardnerella that were associated with refractory responses to oral metronidazole, and less robust recovery of Lactobacillus species associated with recurrence after an initial period of remission. However, these associations did not account for outcomes in all patients, suggesting that other bacterial species were involved. In this follow-up study, we sequenced the V4 domain of 16S rRNA sequences of 41of these same patients pre- and posttreatment. Overall compositions among pretreatment clinical outcome groups were not different, although alpha diversity significantly decreased: refractory > recurrent > remission. Combinations of key species were associated with and prognostic for outcome. Higher pretreatment abundance of Megasphaera lornae together with lower abundance of Gardnerella Gsp07 and Finegoldia magna predicted long term remission after oral metronidazole. Furthermore, a subset of refractory patients that did not have high levels of Gardnerella Gsp07, instead had elevated levels of alternative species including Atopobium vaginae, Mageeibacillus indolicus (BVAB3), and Prevotella timonensis. Patients who recurred after transient remission had elevated abundance of species including Atopobium vaginae, Gardnerella, and Aerococcus christensenii, compared to long-term remission patients. Core bacterial species among refractory patients did not change in abundance after metronidazole, suggesting resistance or tolerance, in contrast to the loss in abundance of the same species among recurrent or remission patients. These findings have potential prognostic and therapeutic implications.

The role of vaginal microecology in the cervical cancer

AIM

To explore the role of vaginal microecology in cervical cancer, so as to increase the understanding of cervical cancer and lay a foundation for future large-sample clinical trials.

METHODS

We reviewed and summarized the literature comprehensively, and discussed the relationship between vaginal microecology and HPV infection, CIN progression and cervical cancer, as well as the potential molecular mechanism and the prospects of probiotics and prebiotics in future cancer treatments.

RESULTS

With the popularization of high-throughput sequencing technology and the development of bioinformatics analysis technology, many evidences show that the increase in the diversity of the bacterial community in the vaginal microecological environment and the decrease in the number of Lactobacilli are associated with the continuous infection of HPV and the further development of CIN, cervical cancer-related.

CONCLUSIONS

Vaginal microecological imbalance has an important impact on the occurrence and development of cervical cancer. However, the pathogenesis is not completely clear, and more high-level basic research and longitudinal clinical studies are needed to verify.

Host and Microbiome Interplay Shapes the Vaginal Microenvironment

The female reproductive tract harbors a unique microbiome, especially the vagina. The human vaginal microbiome exhibits a low diversity and is dominated by Lactobacillus species, compared to the microbiome of other organs. The host and vaginal microbiome mutually coexist in the vaginal microenvironment. Host cells provide Lactobacillus glycogen as an energy source, and Lactobacillus produce lactic acid, which lowers vaginal pH thereby preventing growth of other bacteria. Bacterial vaginosis can modulate host immune systems, and is frequently associated with various aspects of disease, including sexually transmitted infection, gynecologic cancer, and poor pregnancy outcomes. Because of this, numerous studies focused on the impact of the vaginal microbiome on women`s health and disease. Furthermore, numerous epidemiologic studies also have demonstrated various host factors regulate the vaginal microbiome. The female reproductive tract undergoes constant fluctuations due to hormonal cycle, pregnancy, and other extrinsic factors. Depending on these fluctuations, the vaginal microbiome composition can shift temporally and dynamically. In this review, we highlight the current knowledge of how host factors modulate vaginal microbiome composition and how the vaginal microbiome contributes to maintaining homeostasis or inducing pathogenesis. A better understanding of relationship between host and vaginal microbiome could identify novel targets for diagnosis, prognosis, or treatment of microbiome-related diseases.

Human Trial for the Effect of Plasma-Activated Water Spray on Vaginal Cleaning in Patients with Bacterial Vaginosis

Underwater plasma discharge temporally produces several reactive radicals and/or free chlorine molecules in water, which is responsible for antimicrobial activity. Hence, it can simply sanitize tap water without disinfectant treatment. Additionally, the spraying technique using cleaning water exploits deep application in the narrow and curved vaginal tract of patients. Herein, we attempted a clinical trial to evaluate the vaginal cleaning effect of spraying plasma-activated water (PAW) to patients with vaginitis (46 patients). The efficacy was compared with treatment with betadine antiseptics used to treat bacterial vaginosis (40 patients). To evaluate the cleaning effect, Gram staining of the vaginal secretions was conducted before and after spraying PAW or betadine treatment (BT). Consequently, PAW-sprayed (PAWS) patients (22.3%) showed a better vaginal cleaning effect against Gram-positive and -negative bacteria than BT patients (14.4%). Moreover, 18 patients in the BT group showed worsened vaginal contamination, whereas five patients in the PAWS group showed worsened vaginal contamination. Taken together, the noncontact method of spraying cleaning water to the vagina exhibited a reliable vaginal cleaning effect without further bacterial infection compared with BT. Therefore, we suggest a clinical application of the spraying method using PAW for vaginal cleaning to patients with vaginitis without disinfectants and antibiotics.

Gardnerella vaginalis clades in pregnancy: New insights into the interactions with the vaginal microbiome

Gardnerella vaginalis (GV) is an anaerobic bacterial species involved in the pathogenesis of bacterial vaginosis (BV), a condition of vaginal dysbiosis associated with adverse pregnancy outcomes. GV strains are categorized into four clades, characterized by a different ability to produce virulence factors, such as sialidase. We investigated the distribution of GV clades and sialidase genes in the vaginal ecosystem of a cohort of pregnant women, assessing the correlations between GV clades and the whole vaginal microbiome. A total of 61 Caucasian pregnant women were enrolled. Their vaginal swabs, collected both at the first and third trimester of pregnancy, were used for (i) evaluation of the vaginal status by Nugent score, (ii) vaginal microbiome profiling by 16S rRNA sequencing, (iii) detection and quantification of GV clades and sialidase A gene by qPCR assays. DNA of at least one GV clade was detected in most vaginal swabs, with clade 4 being the most common one. GV clade 2, together with the presence of multiple clades (>2 simultaneously), were significantly associated with a BV condition. Significantly higher GV loads and sialidase gene levels were found in BV cases, compared to the healthy status. Clade 2 was related to the major shifts in the vaginal microbial composition, with a decrease in Lactobacillus and an increase in several BV-related taxa. As the number of GV clades detected simultaneously increased, a group of BV-associated bacteria tended to increase as well, while Bifidobacterium tended to decrease. A negative correlation between sialidase gene levels and Lactobacillus, and a positive correlation with Gardnerella, Atopobium, Prevotella, Megasphaera, and Sneathia were observed. Our results added knowledge about the interactions of GV clades with the inhabitants of the vaginal microbiome, possibly helping to predict the severity of BV and opening new perspectives for the prevention of pregnancy-related complications.

Cervicovaginal loads of Gardnerella spp. are increased in immunocompetent women with persistent high-risk human papillomavirus infection

Introduction. Two high-oncogenic-risk human papilomavirus (hrHPV) genotypes - HPV16 and HPV18 - cause most of the cases of cervical cancer worldwide. Bacterial vaginosis is associated with increased hrHPV persistence, although the mechanism underlying this association remains unclear. Gardnerella spp. are detected in nearly all cases of bacterial vaginosis and are the major source of cervicovaginal sialidases. The NanH1 gene is present in virtually all Gardnerella sialidase-producing strains and has been proposed as a potential marker for persistent hrHPV infection.Hypothesis. Gardnerella spp. load and the NanH1 gene are associated with hrHPV persistence.Aim. To compare the cervicovaginal load of Gardnerella spp. and the frequency of the NanH1 gene between women with persistent HPV16 and/or HPV18 infection and those who cleared the infection after 11 months.Methodology. Among a population of 1638 HPV screened, we detected 104 with positive HPV16 and/or HPV18 results. Samples were obtained at two time points (baseline and at a median of 11 months at follow-up) and tested using the Linear Array HPV Genotyping kit (Roche Molecular Systems, Pleasanton, CA, USA). Based on their HPV16/HPV18 status at enrolment and follow-up, participants were assigned to 'persistence' or 'clearance' groups. We used cervicovaginal fluid samples obtained upon enrolment to determine the load of the 23 s rRNA gene of Gardnerella spp. and the presence of the NanH1 gene using real-time polymerase chain reaction (PCR). We compared Gardnerella spp. loads and NanH1 frequency between the groups by, respectively, Mann-Whitney and chi-squared tests, with a P-value <0.05 considered to be significant.Results. Of the 104 participants who were positive for HPV16/HPV18, 73 (70.2 %) persisted with at least 1 of the baseline genotypes at follow-up, while 31 (29.8 %) cleared the infection in this time frame. Participants in the persistence group had significantly higher loads of Gardnerella spp. [5.8E+02 (0-3.0E+05) copies µl^-1] than those in the clearance group [9.9E+01 (0-7.7E+04) copies µl^-1] (P=0.03). The baseline frequency of NanH1 was higher in the persistence' (n=46, 63.0 %) than in the clearance (n=14, 45.2 %) group, although this was not statistically significant (P=0.09).Conclusion. These findings reinforce the negative effect of vaginal microbiota for the clearance of hrHPV and indicate a possible association between sialidase-producing species with hrHPV persistence.

Six Bacterial Vaginosis-Associated Species Can Form an In Vitro and Ex Vivo Polymicrobial Biofilm That Is Susceptible to Thymbra capitata Essential Oil

Bacterial vaginosis (BV) is associated with serious gynaecologic and obstetric complications. The hallmark of BV is the presence of a polymicrobial biofilm on the vaginal epithelium, but BV aetiology is still a matter of debate. We have previously developed an in vitro biofilm model that included three BV-associated species, but, up to now, no studies are available whereby more bacterial species are grown together to better mimic the in vivo situation. Herein, we characterized the first polymicrobial BV biofilm consisting of six cultivable BV-associated species by using both in vitro and ex vivo vaginal tissue models. Both models revealed that the six species were able to incorporate the polymicrobial biofilm, at different bacterial concentrations. As it has been thought that this polymicrobial biofilm may increase the survival of BV-associated species when exposed to antibiotics, we also assessed if the Thymbra capitata essential oil (EO), which has recently been shown to be highly bactericidal against several Gardnerella species, could maintain its anti-biofilm activity against this polymicrobial biofilm. Under our experimental conditions, T. capitata EO exhibited a high antibacterial effect against polymicrobial biofilms, in both tested models, with a significant reduction in the biofilm biomass and the number of culturable cells. Overall, this study shows that six BV-associated species can grow together and form a biofilm both in vitro and when using an ex vivo model. Moreover, the data obtained herein should be considered in further applications of T. capitata EO as an antimicrobial agent fighting BV.